scholarly journals Inhibition of caspase-8 activity reduces IFN-gamma expression by T cells from Leishmania major infection

2008 ◽  
Vol 80 (1) ◽  
pp. 129-136 ◽  
Author(s):  
Wânia F. Pereira ◽  
Landi V.C. Guillermo ◽  
Flávia L. Ribeiro-Gomes ◽  
Marcela F. Lopes
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Cd8 T Cells ◽  
Leishmania Major ◽  
Caspase 8 ◽  
Ifn Gamma ◽  
Major Infection ◽  
Draining Lymph Nodes

Following infection with Leishmania major, T cell activation and apoptosis can be detected in draining lymph nodes of C57BL/6-infected mice. We investigated the mechanisms involved in apoptosis and cytokine expression following Tcellactivation. After two weeks of infection, apoptotic T cells were not detected in draining lymph nodes but activation with anti-CD3 induced apoptosis in both CD4 and CD8 T cells. Treatment with anti-FasLigand, caspase-8 or caspase- 9 inhibitors did not block activation-induced T-cell death. We also investigated whether the blockade of caspase-8 activity would affect the expression of type-1 or type-2 cytokines. At early stages of infection, both CD4 and CD8 T cells expressed IFN-gamma upon activation. Treatment with the caspase-8 inhibitor zIETD-fmk (benzyl-oxycarbonyl-Ile- Glu(OMe)-Thr-Asp(OMe)-fluoromethyl ketone) reduced the proportion of CD8 T cells and IFN-gamma expression in both CD4 and CD8T cells. We conclude that a non apoptotic role of caspase-8 activity may be required for T cell-mediated type-1 responses during L. major infection.

scholarly journals Combination Immune Treatment of a Highly Aggressive Orthotopic Murine Glioblastoma With Checkpoint Blockade Inhibition and Neoantigen Vaccination

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Connor Liu ◽  
Maximilian Schaettler ◽  
Jay Bowman-Kirigin ◽  
Diane Bender ◽  
Dale K Kobayashi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Cd8 T Cells ◽  
In Silico Analysis ◽  
Checkpoint Blockade ◽  
Therapeutic Interventions ◽  
Attractive Potential ◽  
Missense Mutations ◽  
Draining Lymph Nodes

Abstract INTRODUCTION The treatment of glioblastoma remains a challenge for modern therapy. Checkpoint blockade inhibitors (CBI), designed to block inhibitory T-cell signaling, represent attractive potential therapeutic interventions. However, glioblastoma response rates to CBI remain low. To this end, preclinical models are critical to studying multi-modal immune interventions to overcome CBI resistance. Therefore, we set out to identify endogenous neoantigens in a CBI resistant murine glioblastoma and assess the efficacy of neoantigen vaccination in combination with CBI treatment. METHODS Whole exome DNA and RNA sequencing was used to identify expressed, missense mutations in the C57BL/6 derived murine glioblastoma, CT2A. The pVAC-seq software suite was used to identify candidate neoantigens predicted to bind H2-Kb and H2-Db molecules. CD8 + T cells isolated from CT2A tumor-infiltrating lymphocytes (TIL) were screened for neoantigen reactivity by IFN-gamma enzyme linked immunospot assays. Survival analysis was performed on intracranial tumor bearing mice treated with neoantigen vaccination, anti-PD-L1, or combination therapy. RESULTS In silico analysis identified 649 CT2A-derived candidate neoantigens predicted to bind H2-Kb or H2-Db molecules. Of the 40 top-ranking neoantigen candidates, 16 elicited CD8 + TIL responses in mice vaccinated with cognate peptides. Assessing for endogenous reactivity, we identified neoantigen specific CD8 + T cell responses in the intracranial TIL and draining lymph nodes to two H2-Kb restricted, Epb4 (H471L) and Pomgnt1 (R497L), and one H2-Db restricted neoantigen, Plin2 (G332R). Survival studies showed that therapeutic neoantigen vaccination with Epb4, Pomgnt1, and Plin2, in combination with anti-PD-L1 treatment was superior to anti-PD-L1 alone. CONCLUSION We identified endogenous neoantigen specific CD8 + T cells within brain tumors and draining lymph nodes of a CBI resistant murine glioblastoma. Furthermore, we find that neoantigen vaccination significantly augments survival benefit in combination with anti-PD-L1 treatment. These observations provide important preclinical correlates for glioblastoma immunotherapy trials and support further investigation into the effects of multi-modal immunotherapeutic interventions on anti-glioma immunity.

CD8+ T-cell–mediated killing of donor dendritic cells prevents alloreactive T helper type-2 responses in vivo

Blood ◽  
2006 ◽  
Vol 108 (7) ◽  
pp. 2257-2264 ◽  
Author(s):  
Sophie Laffont ◽  
Jérôme D. Coudert ◽  
Lucile Garidou ◽  
Laurent Delpy ◽  
Aurélie Wiedemann ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Th2 Cell ◽  
Draining Lymph Nodes

Abstract Accumulating evidence indicates that, in absence of CD8+ T-cell activation, CD4+ T-cell–mediated allograft rejection is associated with a dominant Th2-cell response and eosinophil infiltrates. In this study, we analyzed the mechanisms by which CD8+ T cells regulate alloreactive CD4+ T-cell priming and differentiation into interleukin 4 (IL-4)–producing cells. We showed that interferon γ (IFN-γ) production by CD8+ T cells was dispensable for the inhibition of Th2-cell development, as well as tissue eosinophilia and type 2 cytokine production in the rejected grafts. Since we noticed that CD8+ T cells not only suppressed Th2 differentiation, but also down-modulated the overall priming of alloreactive CD4+ T cells, we evaluated whether CD8+ T cells act by limiting the accumulation of donor-derived dendritic cells (DCs) in lymph nodes. We found that indeed, alloreactive CD8+ T cells rapidly eliminated allogeneic DCs from T-cell areas of draining lymph nodes, through a perforin-dependent mechanism. Thus, our data demonstrate that cytotoxic T lymphocyte (CTL)–mediated clearance of allogeneic DCs is a negative feedback mechanism that limits the duration of alloantigen presentation in draining lymph nodes, thereby modulating the amplitude and polarization of the primary alloreactive CD4+ T-cell responses.

scholarly journals Comparative evaluation of T cell receptors in experimental glioma-draining lymph nodes

2021 ◽  
Author(s):  
Jens Blobner ◽  
Michael Kilian ◽  
Chin Leng Tan ◽  
Katrin Aslan ◽  
Khwab Sanghvi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Cd8 T Cells ◽  
Tumor Tissue ◽  
Tumor Model ◽  
Cell Receptor ◽  
Cervical Lymph Nodes ◽  
Inguinal Lymph Nodes ◽  
Draining Lymph Nodes

Abstract Background Glioblastomas, the most common primary malignant brain tumors, are considered immunologically cold malignancies due to growth in an immune sanctuary site. While peptide vaccines have shown to generate intra-tumoral antigen-specific T cells, the identification of these tumor-specific T cells is challenging and requires detailed analyses of tumor tissue. Several studies have shown that CNS antigens may be transported via lymphatic drainage to cervical lymph nodes, where antigen-specific T cell responses can be generated. Therefore, we investigated whether glioma-draining lymph nodes (TDLN) may constitute a reservoir of tumor-reactive T cells. Methods We addressed our hypothesis by flow cytometric analyses of chicken ovalbumin (OVA)-specific CD8 + T cells as well as T cell receptor beta (TCRβ) next-generation-sequencing (TCRβ-NGS) of T cells from tumor tissue, TDLN, spleen, and inguinal lymph nodes harvested from experimental mouse GL261 glioma models. Results Longitudinal dextramer-based assessment of specific CD8 + T cells from TDLN did not show tumor model antigen reactivity. Unbiased immunogenomic analysis revealed a low overlap of TCRβ sequences from glioma-infiltrating CD8 + T cells between mice. Enrichment-scores, calculated by the ratio of productive frequencies of the different TCRβ-CDR3 amino-acid (aa) rearrangements of CD8 + T cells derived from tumor, TDLN, inguinal lymph nodes, and spleen demonstrated a higher proportion of tumor-associated TCR in the spleen compared to TDLN. Conclusions In experimental glioblastoma, our data did not provide evidence that glioma-draining cervical lymph nodes are a robust reservoir for spontaneous glioma-specific T cells highlighting the requirement of detailed analyses of glioma-infiltrating T cells for the discovery of tumor-specific TCR.

scholarly journals T cell and non-T cell compartments can independently determine resistance to Leishmania major.

1995 ◽  
Vol 181 (3) ◽  
pp. 845-855 ◽  
Author(s):  
A H Shankar ◽  
R G Titus
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Leishmania Major ◽  
Cell Receptor ◽  
Disease Outcome ◽  
Chimeric Mice ◽  
Antigen Specificity ◽  
Ifn Gamma ◽  
Cell Compartments

In experimental murine cutaneous leishmaniasis caused by Leishmania major (Lm), the cellular determinants governing development of protective or exacerbative T cells are not well understood. We, therefore, attempted to determine the influence of T cell and non-T cell compartments on disease outcome. To this end, T cell chimeric mice were constructed using adult thymectomized lethally irradiated, bone marrow-reconstituted (ATXBM) animals of genetically resistant, C57BL/6, or susceptible, BALB/c, backgrounds. These hosts were engrafted with naive T cell populations from H-2-congenic susceptible, BALB.B6-H-2b, or resistant, C57BL/6.C-H-2d, animals, respectively. Chimeric mice were then infected with Lm, and disease outcome was monitored. BALB/c T cell chimeric mice, BALB/c ATXBM hosts given naive C57BL/6.C-H-2d T cells, resolved their infections as indicated by reductions in both lesion size and parasite numbers. Furthermore, the mice developed typical Th1 (interferon[IFN]-gamma hiinterleukin[IL]-4lo) cytokine patterns. In contrast, both sham chimeric, BALB/c ATXBM hosts given naive BALB/c T cells, and control irradiated euthymic mice succumbed to infection, producing Th2 profiles (IFN-gamma loIL-4hiIL-10hi). C57BL/6 T cell chimeras, C57BL/6 ATXBM hosts given naive BALB.B6-H-2b T cells, resolved their infections as did C57BL/6 sham chimeras and euthymic controls. Interestingly, whereas C57BL/6 control animals produced Th1 cytokines, chimeric animals progressed from Th0 (IFN-gamma hiIL-4hiIL-10hi) to Th2 (IFN-gamma loIL-4hiIL-10hi) cytokine profiles as cure ensued. Both reconstitution and chimeric status of all mice were confirmed by flow cytometry. In addition, T cell receptor V beta usage of Lm-specific blasts was determined. In all cases, V beta use was multiclonal, involving primarily V beta 2, 4, 6, 8.1, 8.2, 8.3, 10, and 14, with relative V beta frequencies differing between H-2b and H-2d animals. Most importantly, however, these differences did not segregate between cure and noncure outcomes. These findings indicate that: (a) genetic traits determining cure in Lm infection can direct disease outcome from both T cell and non-T cell compartments; (b) the presence of the curing genotype in only one compartment is sufficient to confer cure; (c) curing genotype T cells autonomously assume a Th1 cytokine profile-mediating cure; (d) noncuring genotype T cells can mediate cure in a curing environment, despite the onset of Th2 cytokine production; and lastly, (e) antigen specificity of responding T cells, as assessed by V beta T cell receptor diversity, is not a critical determinant of disease outcome.

scholarly journals Cytomegalovirus inhibition of extrinsic apoptosis determines fitness and resistance to cytotoxic CD8 T cells

2020 ◽  
Vol 117 (23) ◽  
pp. 12961-12968 ◽  
Author(s):  
M. Zeeshan Chaudhry ◽  
Rosaely Casalegno-Garduno ◽  
Katarzyna M. Sitnik ◽  
Bahram Kasmapour ◽  
Ann-Kathrin Pulm ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antigen Presentation ◽  
Cd8 T Cells ◽  
Cell Function ◽  
Death Receptor ◽  
Cd8 T Cell ◽  
Cytotoxic T Cell ◽  
Caspase 8 ◽  
Infected Cells

Viral immune evasion is currently understood to focus on deflecting CD8 T cell recognition of infected cells by disrupting antigen presentation pathways. We evaluated viral interference with the ultimate step in cytotoxic T cell function, the death of infected cells. The viral inhibitor of caspase-8 activation (vICA) conserved in human cytomegalovirus (HCMV) and murine CMV (MCMV) prevents the activation of caspase-8 and proapoptotic signaling. We demonstrate the key role of vICA from either virus, in deflecting antigen-specific CD8 T cell-killing of infected cells. vICA-deficient mutants, lacking either UL36 or M36, exhibit greater susceptibility to CD8 T cell control than mutants lacking the set of immunoevasins known to disrupt antigen presentation via MHC class I. This difference is evident during infection in the natural mouse host infected with MCMV, in settings where virus-specific CD8 T cells are adoptively transferred. Finally, we identify the molecular mechanism through which vICA acts, demonstrating the central contribution of caspase-8 signaling at a point of convergence of death receptor-induced apoptosis and perforin/granzyme-dependent cytotoxicity.

scholarly journals Dermal Vγ4 + γδ T Cells Possess a Migratory Potency to the Draining Lymph Nodes and Modulate CD8 + T-Cell Activity through TNF-α Production

2015 ◽  
Vol 135 (4) ◽  
pp. 1007-1015 ◽  
Author(s):  
Satoshi Nakamizo ◽  
Gyohei Egawa ◽  
Michio Tomura ◽  
Shunsuke Sakai ◽  
Soken Tsuchiya ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Cell Activity ◽  
Γδ T Cells ◽  
Cd8 T Cell ◽  
Tnf Α ◽  
Draining Lymph Nodes

scholarly journals Intralymphatic GAD-alum Injection Modulates B Cell Response and Induces Follicular Helper T Cells and PD-1+ CD8+ T Cells in Patients With Recent-Onset Type 1 Diabetes

2022 ◽  
Vol 12 ◽  
Author(s):  
Hugo Barcenilla ◽  
Mikael Pihl ◽  
Jeanette Wahlberg ◽  
Johnny Ludvigsson ◽  
Rosaura Casas
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
B Cells ◽  
Lymph Nodes ◽  
Cd8 T Cells ◽  
Helper T Cells ◽  
Follicular Helper T Cells ◽  
Recent Onset ◽  
Follicular Helper

Antigen-specific immunotherapy is an appealing strategy to preserve beta-cell function in type 1 diabetes, although the approach has yet to meet its therapeutic endpoint. Direct administration of autoantigen into lymph nodes has emerged as an alternative administration route that can improve the efficacy of the treatment. In the first open-label clinical trial in humans, injection of aluminum-formulated glutamic acid decarboxylase (GAD-alum) into an inguinal lymph node led to the promising preservation of C-peptide in patients with recent-onset type 1 diabetes. The treatment induced a distinct immunomodulatory effect, but the response at the cell level has not been fully characterized. Here we used mass cytometry to profile the immune landscape in peripheral blood mononuclear cells from 12 participants of the study before and after 15 months of treatment. The immunomodulatory effect of the therapy included reduction of naïve and unswitched memory B cells, increase in follicular helper T cells and expansion of PD-1+ CD69+ cells in both CD8+ and double negative T cells. In vitro stimulation with GAD65 only affected effector CD8+ T cells in samples collected before the treatment. However, the recall response to antigen after 15 months included induction of CXCR3+ and CD11c+Tbet+ B cells, PD-1+ follicular helper T cells and exhausted-like CD8+ T cells. This study provides a deeper insight into the immunological changes associated with GAD-alum administration directly into the lymph nodes.

scholarly journals SARS-CoV-2-reactive interferon-γ-producing CD8+ T cells in patients hospitalized with Coronavirus viral disease-2019

2020 ◽  
Author(s):  
Estela Gimenez ◽  
Eliseo Albert ◽  
Ignacio Torres ◽  
Maria Jose Remigia ◽  
Maria Jesus Alcaraz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Viral Disease ◽  
T Cell Subsets ◽  
Limited Information ◽  
Igg Antibody ◽  
Prognostic Information ◽  
Ifn Gamma ◽  
Cell Counts

There is limited information on SARS-CoV-2 T-cell immune responses in patients with Covid-19. Both CD4+ and CD8+ T cells may be instrumental in the resolution of and protection from SARS-CoV-2 infection. Here, we tested 25 hospitalized patients with either microbiologically documented Covid-19 (n=19) or highly suspected of having the disease (n=6) for the presence of SARS-CoV-2-reactive- CD69+-expressing interferon-gamma;-producing-(IFN-gamma;) CD8+ T cells by a flow-cytometry for intracelular cytokine staining assay. Two sets of overlapping peptides encompassing the SARS-CoV-2 Spike glycoprotein N-terminal 1-643 amino acid sequence and the entire sequence of SARS-CoV-2 M protein were used simultaneously as antigenic stimulus. Ten patients (40%) had detectable responses, displaying frequencies ranging from 0.15 to 2.7% (median of 0.57 cells/microlitre; range, 0.43-9.98 cells/microlitre). The detection rate of SARS-CoV-2-reactive IFN-gamma; CD8+ T cells in patients admitted to intensive care was comparable (P=0.28) to that in patients hospitalized in other medical wards. No correlation was found between SARS-CoV-2-reactive IFN-gamma; CD8+ T-cell counts and SARS-CoV-2 S-specific antibody levels. Likewise, no correlation was observed between either SARS-CoV-2-reactive IFN-gamma; CD8+ T cells or S-specific IgG-antibody titers and blood cell count or levels of inflammatory biomarkers. In summary, in this descriptive, preliminary study we showed that SARS-CoV-2-reactive IFN-gamma; CD8+ T cells can be detected in a non-negligible percentage of patients with moderate to severe forms of Covid-19. Further studies are warranted to determine whether quantitation of these T-cell subsets may provide prognostic information on the clinical course of Covid-19.

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